EAGER SitS: Emergent Properties during Soil Formation

土壤养活了人类。这些地球物质形成于水、空气以及死的和活的有机体与地球表面的岩石物质的相互作用中。土壤可以形成数千年到数百万年，但土壤可能会在人类的时间范围内因侵蚀而流失。在这项拟议的工作中，将使用创新的传感器和技术来测量和了解细菌如何催化铁和氧在土壤中相互作用，影响水在地下流动的路径。这项工作将集中在宾夕法尼亚州一个由NSF资助的天文台--临界区天文台--的土壤形成方面，那里正在进行大量的努力来了解这种过程。关于微生物如何改变岩石的化学成分，并在岩石变成土壤时将其分解，以及这与地下水流动的关系，将产生新的科学知识。与此同时，新技术将提供有关土壤如何形成的社会相关性的新知识，并将通过与当地博物馆的互动向参观天文台的许多其他教职员工、学生和同事以及公众展示。此外，天文台也是NSF资助的年度地球物理野外课程的所在地，将向每年从代表性不足的群体和社区学院中抽取的本科生传授这两项将要部署的技术。在使用新部署的高风险实验中，将探索生物地球化学反应与侧向水流区域的关系。将在为期一个月到一年的部署中研究两种技术：第一种将测量微生物活动(计时安培法)，第二种将测量水引起的岩石材料体积变化的影响(延时地震监测)。这两种技术都还处于初级阶段，因为它们依赖于新的传感器技术和最先进的解释。将这些技术一起部署在已经进行了许多其他测量的地点将确保最高的成功可能性。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Soils sustain humankind. These earth materials form as water, air, and dead and living organisms interact with rock material at Earth's surface. Soils form over thousands to millions of years and yet soil can be lost to erosion over human time frames. In this proposed work, innovative sensors and techniques will be used to measure and understand how iron and oxygen are catalyzed by bacteria to interact in soils, affecting the pathways where water flows in the subsurface. The work will focus on soil formation at an NSF-funded observatory in Pennsylvania - a Critical Zone Observatory - where a large effort is ongoing to understand such processes. New scientific knowledge will be developed about how micro-organisms change the chemistry of rock and break it open as it turns into soil, and how this relates to subsurface water flow. At the same time, the new techniques will provide new knowledge of societal relevance about how soil forms, and will also be shown to many other faculty members, students, and colleagues that visit the observatory, as well as members of the public through interactions with a local museum. In addition, the observatory is the site of an annual NSF-funded Geophysics field course where the two techniques to be deployed will be taught to an annual cohort of undergraduate students drawn from under-represented groups and community colleges. With high-risk experiments using novel deployments, biogeochemical reactions will be explored with respect to how they relate to zones of lateral water flow. Two techniques will be investigated over month- to year-long deployments: the first will measure microbial activity (chronoamperometry) and the second will measure the effects of water-induced changes in volume of rock materials (time-lapse seismic monitoring). Both techniques are still in their infancy because they depend on new sensor technologies and state-of-the-art interpretations. The deployment of these techniques together in a location where many other measurements have already been made will guarantee the highest likelihood of success.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.